Early mid-adulthood is a period when an increase is seen in indicators of both health risk (e.g., obesity) and poor health. Although studies of the behavioral etiology of poor health frequently focus on individual habits (e.g., diet) and general environmental risk (e.g., socioeconomic status;SES), there is little information available about the potential role of dyadic processes between romantic partners in explaining physical health outcomes in mid-adulthood. Conflictual and dysfunctional romantic relationships are a major cause of unhappiness and stress in adulthood and are associated with domestic violence, high divorce rates, psychopathology, and poor health and adjustment for the partners. Furthermore, there is evidence that some poor health habits are associated across partners. The proposed study will test a comprehensive model for couples from at-risk backgrounds on the basis of a dynamic developmental systems approach and stress and support processes to examine the risk and protective impacts of romantic relationships on health in adulthood. It is posited that both general and specific developmental and relationship risks have significant implications for health outcomes in mid-adulthood, and that effects of such risk factors are mediated by stress sensitive biological indicators of sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA) functioning (cortisol and alpha amylase assayed from saliva) and lower cell-mediated immune function (Epstein-Barr Virus antibodies and C-Reactive Protein assayed from blood spots). In addition, the course of intimate partner violence in early mid-adulthood will be examined. To address the aims, we plan to continue following the young men in the Oregon Youth Study (OYS) and their romantic partners. The OYS men comprise an at-risk community sample first recruited in Grade 4 and assessed yearly, with a current N of 191 and a 94% retention rate. The OYS Couples Study began when the men were in late adolescence, and 195 OYS men have participated in the study. Proposed data collection includes two additional waves 2 years apart, when the men will be in their mid 30s (OYS Couples Study Time 8 and Time 9) and will involve assessment of both partners and observation of a series of discussions, including a problem-solving discussion. Innovative analytic multilevel modeling techniques with a strong focus on social processes within the dyad and on both individual and couple level outcomes will be used to address the hypotheses. PUBLIC HEALTH RELEVANCE: Conflictual and dysfunctional romantic relationships are a major cause of unhappiness in adulthood and are associated with areas of national concern such as intimate partner violence, high divorce rates, chronic stress and poor health. Focus areas of Healthy People 2010 (U.S. DHHS) include prevention and control of a number of chronic diseases (e.g., heart disease, diabetes) as well as a focus on several of the causal risk factors for these diseases (e.g., nutrition and obesity, exercise, substance use). The proposed study will shed new light on the development of poor health in these areas by testing etiological models for the effects of developmental risk, stress, and romantic relationship influences (including negative and positive influences) on stress sensitive biological systems, health habits, and ultimately health outcomes for at-risk lower socioeconomic status couples in early midlife.